package string;

public class StringStringBuilderDemo {
    public static void main(String[] args) {
        /*
        String str="a";
        for(int i=0;i<10000000;i++){
            str=str+i;
        }
        System.out.println("执行完毕");
         */

        String str="a";
        StringBuilder builder=new StringBuilder(str);
        for(int i=0;i<20;i++) {
            builder.append(i);
        }
        System.out.println(builder);

    }
}
